In this alternate reality, demons could be summoned to do your bidding, and the three sacred treasures of Japan hold immense power for any who find them. Having been lost over the centuries, first news of the Kusanagi sword surfaced the human world, and the three clans began to make their move to find all three treasures. Folklore dictates when the three treasures are together, the most treasured secret would be revealed. Between these families, they use all their resources and powerful influences to locate the treasures. The most common practice in the three clans is to make use of their Shinto priests and priestesses to summon demons, and have them servicing the family for which ever purposes needed. Koumajutsu is the act of summoning demons, and this is its era.